Compressed-gas circuit interrupter having two component containing legs upstanding from a grounded u-shaped high pressure tank

ABSTRACT

A compressed-gas circuit interrupter has a generally U-shape with interrupting elements, or terminal-bushing structures, disposed in the upstanding legs of the &#39;&#39;&#39;&#39;U,&#39;&#39;&#39;&#39; depending upon the rating requirements; and a grounded high-pressure chamber constitutes the lower bend of the U-shaped circuit interrupter. The compressed-gas circuit interrupter is of the dual-pressure type in which the one or more pairs of contacts are separated in a high-pressure gaseous environment, and the high-pressure gas exhausts through one or both of the separable contacts themselves. Downstream blast valves control the continued exhaust of gas through the separable contact structure, and in the fully open-circuit position of the interrupter, the contact space contains high-pressure gas, resulting in reduced separation distance between the separated contacts. For the lower ratings, a terminal bushing, preferably of the gaseous type, constitutes one of the legs of the &#39;&#39;&#39;&#39;U&#39;&#39;&#39;&#39; and the interrupting elements are disposed along the other leg of the U. For the higher ratings, both legs of the U may comprise one or more serially related interrupting elements to provide, where desired, a number of serially related arc-extinguishing units. The movable contact structure is preferably actuated pneumatically by a piston structure disposed at the upper end of the arc-extinguishing side of the interrupter, which is controlled by a three-way tripping control valve initiated by an insulating operating rod extending down to ground potential, and mechanically connected to the other phase units of the circuit interrupter, a common valve actuator employed. The legs of the U comprise an outer weatherproof insulating shell and an inner insulating tube, which may be under tension, surrounding the serially related arc-extinguishing units. As stated, the inner insulating tube contains high-pressure gas immediately surrounding the separable contact structure, so that high-pressure gas is immediately available at the contacts for the interrupting operation upon their separation.

United States Patent [721 Inventors Richard E. Kane Monroeville; Frank L. Reese, Pittsburgh, both of, Pa.

[211 App]. No. 782,365

[22] Filed Dec. 9, 1968 [45] Patented July 27, 1971 {73] Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

[54] COMPRESSED-GAS CIRCUIT INTERRUPTER HAVING TWO COMPONENT CONTAINING LEGS UPSTANDING FROM A GROUNDED U-SHAPED HIGH PRESSURE TANK 12 Claims, 25 Drawing Figs.

[52] 1.1.8. Cl 200/148 R,

[51] Int. Cl H0lh 33/56,

H01 h 33/74 [50] Field otSearch 200/148, 148.5, 144.2,145, 148.6, 148.2

[56] References Cited UNITED STATES PATENTS 2,766,348 10/1956 Forwald 200/148 B 3,189,718 6/1965 Tominaga... 200/148 B 2,979,591 4/1961 Friedrich.... 200/145 X 3,025,375 3/1962 Frank ZOO/144.2

3,236,982 2/1966 Gonek et a1. 200/148 FOREIGN PATENTS 1,304,411 8/1962 France 200/145 1,323,018 2/1963 France 200/148 1,047,877 11/1966 Great Britain.. 200/148 367,878 4/1963 Switzerland 200/ 148 Primary Examiner-Robert Schaefer Assistant Examiner-Robert A. Vanderhye LOW PRESSURE (60 PS1) FOR EXAMPLE Attorneys-A T. Stratton, W. R. Crout and Clement L.

McHale ABSTRACT: A compressed-gas circuit interrupter has a generally U-shape with interrupting elements, or terminalbushing structures, disposed in the upstanding legs of the U, depending upon the rating requirements; and a grounded high-pressure chamber constitutes the lower bend of the U- shaped circuit interrupter. The compressed-gas circuit interrupter is of the dual-pressure type in which the one or more pairs of contacts are separated in a high-pressure gaseous environment, and the high-pressure gas exhausts through one or both of the separable contacts themselves. Downstream blast valves control the continued exhaust of gas through the separable contact structure, and in the fully open-circuit positionof the interrupter, the contact space contains high-pressure gas, resulting in reduced separation distance between the separated contacts.

For the lower ratings, a terminal bushing, preferably of the gaseous type, constitutes one of the legs of the U and the interrupting elements are disposed along the other leg of the U. For the higher ratings, both legs of the U may comprise one or more serially related interrupting elements to provide, where desired, a number of serially related arc-extinguishing units.

The movable contact structure is preferably actuated pneumatically by a piston structure disposed at the upper end of the arc-extinguishing side of the interrupter, which is controlled by a three-way tripping control valve initiated by an insulating operating rod extending down to ground potential,

and mechanically connected to the other phase units of the circuit interrupter, a common valve actuator employed.

The legs of the U comprise an outer weatherproof insulating shell and an inner insulating tube, which may be under tension, surrounding the serially related arc-extinguishing units. As stated, the inner insulating tube contains highpressure gas immediately surrounding the separable contact structure, so that high-pressure gas is immediately available at the contacts for the interrupting operation upon their separation.

PATENTED mm m:

sum 01 0F 1 INVENTORS E Kane L Reese [P W nllll HHV FIG.I3.

FIG. l4.

WITNESSES PATENTEU JULP? 191 S EET 02 HF 13 mm3mmwma BOJJ NQE PATENHB m2? an 596. [P8

saw on or 13 HIGH PRESSURE SF GAS PATENTEflJummn 3,596,028

SHEET U8 0F 13 FIGS.

LOW PRESSURE (60 PSI) FOR EXAMPLE HIGH PRESSURE (230 PSI) FOR EXAMPLE HIGH PRESSURE (230 PSI) FOR EXAMPLE PATENTED JUL27 I97! SHEET 07 [1F 1 RELATIVELY LOW PRESSUREQSPSI) FOR EXAMPLE PATENTED JUL2 7 lH/i SHEET ua 0F 13 HIGH PRESSURE SF GAS FIG. 7?

HIGH PRESSURE SF GAS PATENTED JUL2 1 IBM SHEET 09 [1F 13 PRESSURE (23OPSI) FOR EXAMPLE PATENTEI] JUL27 :91: 3, 596, 028

SHEET 10 [1F 13 FIGS.

PATENTEUJULZYIJH 3 596,028

SHEET 12 0F 13 LOW PRESSURE GAS HIGH PRESSURE SP GAS 13 .Li A O EV A Q 11 l9 l3 P} t, e e O 4| m l O Q C FIG.|6.

FIG. IT

PATENTEDJULPHHYI 33, 963028 sum 13 0F 13 FIG. 18. FIG. I9. FIGZO.

FIG.22.

COMPRESSED-GAS CIRCUIT INTERRUPTER HAVING TWO COMPONENT CONTAINING LEGS UPSTANDING FROM A GROUNDED U-SI-IAPED HIGH PRESSURE TANK CROSS-REFERENCES TO RELATED APPLICATIONS US Pat. application filed Sept. 16, 1968, Ser. No. 759,992 by Lee E. Berkebile sets forth and claims the general manner of arc interruption. U.S. Pat. application filed Sept. 25, 1968, Ser. No. 762,479 by William H. Fischer and Wayne S. Aspey describes and claims one form of operating mechanism for the aforesaid compressed-gas circuit interrupter. U.S. Pat. application filed Dec. 10, I968, Ser. No. 782,631 by William H. Fischer and Wayne 8. Aspey discloses an alternate type of operating mechanism, which may be used with the aforesaid circuit interrupter.

U.S. Pat. application filed Nov. 18, 1968, Ser. No. 776,510 by William H. Fischer and Wayne S. Aspey discloses and claims an operating mechanism for the aforesaid circuit interrupter.

U.S. Pat. application filed Oct. 28, I968, Ser. No. 77l,l 13 by William H. Fischer and Charles Cromer discloses certain features of the separable contact structure and the manner of arc interruption.

BACKGROUND OF THE INVENTION lating casing structure having generally vertically aligned separable contact structures with a compressed-gas blast valve disposed at the lower end of the structure, and many times at a considerable distance away from the separable contact structure. This, of course, necessarily involved a considerable time delay before the operation of the blast valve would permit the gas to flow upwardly into the immediate area of the separable contact structure. The result was a relatively slow-acting circuit breaker. U.S. Pat. No. 2,495,156 issued Jan. 17, 1950 by B. P. Baker is typical of such a structure.

Another type of design, which involves breakers of relatively high-voltage rating, utilizes a pressurized metallic tank at high potential, within which separable contact structure is opened and the high-pressure gas may be exhausted directly to the atmosphere. The metallic tank is supported at a considerable distance up in the air, and the operating rods for the valve structure, the contacts being pneumatically operated, extends downwardly through the upstanding insulating structure to ground potential. U.S. Pat. No. 3,l52,283 by R. B. Shores and U.S. Pat. No. 3,336,454 by .I. W. Beatty et al. generally illustrates this type of structure.

Still a further type of relatively modern structure utilizes a metal tank at high potential, supported at a considerable distance up in the air by an insulating cylindrical support; and

v the tank is at a relatively low pressure. Disposed within the metallic tank at high potential, is a chamber constituting a high-pressure reservoir, which has a blast valve associated therewith and a generally rotating double-break contact structure. The arrangement is such that the contact structure is rotated, establishing two breaks, and at the same time opening the blast valve, which is on the axis of the rotating contact structure. The high-pressure gas passes, in diametrically opposite directions, through the hollow legs of the rotating contact structure, and is blasted past the arc and into the general interior ofthe metallic tank. U.S. Pat. No. 3,327,082 by RC. Van Sickle et al. generally illustrates this type of structure.

SUMMARY OF THE INVENTION As pointed out above, compressed-gas circuit interrupters have assumed many diverse shapes in the past. In general, it is a distinct objective for modern compressed-gas circuit interrupters to have a rapid response, and be capable of say, for example, two-cycle operation. In addition, to accommodate various ratings, and not to stock an inventory of many different parts for different ratings, it is generally desirable to provide a structure, which may accommodate a number of ratings, and yet utilize standard parts of few number.

Accordingly, it is a general object of the present invention to provide an improved compressed-gas circuit interrupter of a different configuration, resulting in a compact shape and adaptable for a wide variety of voltage and current ratings utilizing, generally, the same parts, with but few modifications.

Generally, this is accomplished by providing a generally U- shape of circuit interrupter in which one or both legs of the U may include serially related arc-extinguishing units. For the lower ratings, one of the legs of the U may constitute a terminal-bushing structure. For the higher ratings, this same leg may be utilized to accommodate one or more serially related arc-extinguishing units to fortify, or increase, the number of units provided by the other leg of the circuit interrupter. Thus, high voltages may be adapted.

Generally, the circuit interrupter of the present invention utilizes a generally U-shaped configuration, as mentioned, and the lower bend of the U constitutes a high-pressure reservoir. The upstanding leg, which surrounds the arc-extinguishing elements, is of a pressurized construction, and places the highpressure gas directly at the separable contact structure. During arc interruption, the high-pressure gas, immediately available at the separable contact structure, passes through the interior of one or both of the separable contacts, and is controlled by one or more downstream blast valves, which may be mechanically controlled by the movable contact structure.

The circuit interrupter of the present invention utilizes a pneumatic operator at the top of the arc-extinguishing assemblage constituting one leg of the U and is controlled by a three-way tripping control valve, itself controlled by an insulating operating rod extending downwardly interiorly of the leg to the ground-potential operating mechanism, which may also be utilized to control the other phase-units of the interrupter. As a result, the tripping control valves for all three phase-units may be simultaneously actuated to result thereby in the several individual piston structures being operated to open mechanically the movable contact structures for all of the arc-extinguishing assemblages of the several phases.

Accordingly, a general object of the present invention is to provide an improved compressed-gas circuit interrupter, particularly adaptable for the higher voltage ratings.

Another object of the present invention is to provide an improved compact type of circuit interrupter readily adaptable for different ratings, yet involving relatively few parts.

Another object of the present invention is the provision of an improved compressed-gas circuit interrupter involving separable contact structures disposed in a high-pressure environment, in which the high-pressure gas is enclosed within an insulating generally upstanding cylinder.

Still a further object of the present invention is the provision of an improved compressed-gas circuit interrupter, a highspeed operation, in which a pneumatic operator at high potential actuates the movable contact structure for each arc-extinguishing assemblage.

Still a further object of the present invention is the provision of an improved compressed-gas circuit interrupter involving relatively few parts, highly reliable, and adaptable for a wide variety of circuit interrupter ratings.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end elevational view of a three-phase circuit interrupter embodying the principles of the present invention;

FIG. 2 is a side elevational view of the three-phase circuit interrupter of FIG. 1;

FIG. 3 is a top plan view of the circuit interrupter of FIGS. 1 and 2;

FIG. 4 is a diagrammatic view illustrating the interconnecting mechanical linkage between the ground potential operator and the insulating control rods extending upwardly to control the valves at the upper ends of the arc-extinguishing assemblages;

FIGS. 5A5B-5C collectively illustrate a vertical cross section through the circuit interrupter of the present invention, the contact structure being illustrated in the closed-circuit position;

FIG. 6 is an enlarged vertical sectional view taken through the upper end of the arc-extinguishing assemblage illustrating the pneumatic operator and the contact structure in the closed-circuit position;

FIG. 7 is a vertical sectional view, partly in side elevation, of a separable contact structure, the contacts being illustrated in the closed-circuit position;

FIG. 8 is a similar view illustrating the contact structure in the fully open-circuit position;

FIG. 9 is a vertical sectional view, partly in side elevation, of a modified-type of arc-extinguishing assemblage involving two serially related contact structures particularly adapted for the higher voltage ratings, the contacts being in the closed-circuit position;

FIG. 10 is an enlarged vertical sectional view taken through the lower end of the arc-extinguishing assemblage illustrating the lower ends of the valve control rods;

FIG. 11 is a detailed view taken in the direction of the arrows Xl-XI of FIG. 10;

FIG. 12 is a detailed v ew of the upper deflector base;

FIG. 12A is a vertical sectional view taken through the deflector base of FIG. 12;

FIGS. 13, I4 and 15 illustrate details of the latching arrangement for the movable contact structure;

FIG. 16 is a plan view in section, taken substantially along the line XVI-XVI of FIG. 6;

FIG. 17 is a sectional view of an actuator arm;

FIGS. 18, 19 and 20 illustrate variations in rating, which may be readily accomplished by the use of the generally U- shaped construction of the presently described circuit interrupter; and

FIGS. 21 and 22 are, respectively, plan and partial end views of the blast-valve activator.

DESCRIPTION OF THE PREFERRED EMBODIlI/IENTS Referring to the drawings, and more particularly to FIGS. 13 thereof, the reference numeral 1 generally designates a three-phase circuit breaker. As shown in FIGS. 1-3, it will be apparent that the circuit breaker structure 1 is supported by a metallic framework 2, which may be composed of heavy angle-iron braces 3 and struts 4. The circuit breaker structure 1 is generally of the dual-pressure type involving the use of a suitable arc-extinguishing gas 5 at two different pressures, namely a high pressure say 230 p.s.i. suitable for use for injecting into the are 6 (FIG. 7) to effect the extinction thereof, and, additionally, being used in the operating mechanism 7 (FIG. 6) to effect actuation of the piston structure 8 associated therewith and a low pressure, say 60 p.s.i. for example.

Generally, as shown in FIGS. 2 and 3, the several pole-units A, B, and C are spaced laterally apart upon the grounded supporting framework 2, and are mechanically interconnected to a common mechanism 10 at ground potential, diagrammatically indicated in FIG. 4 of the drawings.

Briefly, the manner of operation of the circuit breaker structure I is such as to cause the actuation of the ground potential operator 10 to effect motion ofa mechanical linkage II, which interconnects the several three-way valve control rods 13 extending upwardly individually within the three arcextinguishing assemblages 15, more clearly shown in FIGS. 2 and 3 of the drawings. As illustrated diagrammatically in FIG. 5A of the drawings, the valve control rod 13, moving only a short distance, extends upwardly within insulating supporting tubes 17 disposed interiorly of an insulating inner tension tube 18 serving to spacially relate the one or more pairs of contact structures 20, which may be employed. As shown in FIGS. 5A, only a single pair of separable contact structures 20 is utilized; however, for the higher voltages and higher ratings, as shown in FIGS. 9 and 19, a plurality of pairs of contact structures 20 may be utilized, if desired.

Generally, the arc-extinguishing assemblage 15 comprises an outer insulating weatherproof casing 22, which may be formed either of porcelain, or of a suitable resinous material serving to enclose the arc-extinguishing structure 24 of the interrupter 1. The arc-extinguishing structure, or assemblage 15 is supported upon the grounded housing 26 and is slanted, or canted away from a terminal-bushing structure 28, which. serves to cause the current path to be conducted in a generally U-shape. The terminal-bushing structure 28 generally has a terminal rod 29 at high voltage extending therethrough, and is spaced within an outer weatherproof casing 30, composed of a suitable insulating material, such as porcelain. A suitable arcextinguishing gas, which has high insulating qualities, may be enclosed within the terminal-bushing structure 28 at a relatively low pressure, say of 25 p.s.i. This gas may be the same gas 5 as described heretofore, but at a much lower pressure.

FIGS. 5A-5B5C collectively show a vertical cross-sectional view taken through a single pole unit A of the threephase circuit interrupter 1. As well known by those skilled in the art, there are three such structures A, B" and C" to control the three-phases of a transmission system.

In the circuit breaker structure I under consideration, a suitable highly effective arc-extinguishing gas 5, such as sulfur-hexafluride (SF gas, may be used as the arc-extinguishing gas, and also as an insulating gas to enable a close spacing of the live parts. It is also used as the insulating gas within the terminal-bushing structure 28. US. Pat. No. 2,757,261

describes the arc-extinguishing characteristics of this particular gas 5.

As mentioned hereinbefore, generally, the manner of operation of the circuit interrupter is the simultaneous actuation of the three-valve control tripping rods 13, which extend upwardly into the top of the arc-extinguishing assemblages 15. Here as is shown more clearly in FIG. 6 of the drawings, the upper ends of the valve control tripping rods 13 are biased upwardly by a battery of compression springs 31 seating upon a spring seat 32 affixed to the valve control rod 13, as at 34, and serving to bias the pressure-balanced three-way control valve 36 to its upper closed position. To effect an opening operation of the circuit breaker 1, the valve control rod 13 is moved upwardly, say three-quarters of an inch,-so as to permit the admission of high-pressure gas 5, existing within the region 37, upwardly through a conduit 39 and across the entire lower surface of a dual-acting piston structure 8, which is connected, by means of a piston rod 41, to the movable contact structure 20 of the interrupter 1.

As shown more clearly in FIG. 6, taken in conjunction with FIG. 7, it will be observed that the piston structure 8 is mechanically tied, by means of the piston rod 41, to a generally ladder-shaped structure 43, which comprises a pair of laterally spaced insulating operating rods 44, which extend axially of the arc-extinguishing assemblage 15 through a pair of hollow supporting tubes 45.

The region 47, immediately adjacent the contact structure 20, and externally thereof in the closed-circuit position thereof, as illustrated in FIG. 8, is at a relatively high pressure, say 230 p.s.i. as more clearly described in the US. Pat. application filed Sept. 16, I968 Ser. No. 759,992 by Lee E. Berkebile, the arc-extinguishing structure, or unit 24 being of the socalled downstream type, in which the high-pressure gas 5 moves into and through the separated contact structure 20, during the opening operation, until the flow of gas is halted by the closing operation of a pair of downstream, or secondary blast valves, indicated by the reference numerals 49 and 50in FIG. 7 of the drawings.

With reference to FIG. 6 of the drawings, it will be observed that the dual-acting piston 8 has a differential annular area 8x equal to the difference of area of 8a8d, herein termed the effective closing area portion of the piston 8. This effective closing area 8x is constantly subjected to a high-pressure gas within the region 51. In addition, the piston structure 8 has the upper closing face portion 8b thereof constantly subjected to gas at a relatively low pressure, say 60 p.:s.i., for example, which tends to effect closing operation of the piston 8, and hence the movable contact structure 20. The annular area, which is effective in opening the mechanism, is 8c8x. The area, which is effective in opening the mechanism, is 8c-8x. The area, which is effective for the opening shock absorber, is 8a. area that is effective for the closing shock absorber is 8d.

To effect an opening operation of the interrupter l, actuation of the three-way control valve 36 is brought about by upward movement of the valve-control tripping rod 13 to admit high-pressure gas upon the lower face 80 of the piston structure 8 causing thereby opening upward motion of the contact structure 20, and, additionally, trapping high-pressure gas within the space 51 for shock-absorbing action and causing its slow leakage through the ports 53 provided in the annular check valve 54. During the closing operation, upon downward movement of the piston structure 8, the check valve 54 associated with this shock absorber raises, and permits highpressure gas, which is constantly present within the region 56, to flow past the ring-shaped check valve 54 and into the shock-absorbing region 51.

During the closing operation, the downward movement of the piston structure 8 effects the downward movement of a stepped portion 8d thereof into the space 58, which contains gas at relatively high pressure. This performs a shock-absorb ing function during the closing stroke, the gas leaking through perforations 59 provided in a ring-shaped check valve 60.

Fixedly attached to the piston structure 8 and in effect constituting an extension of the piston rod 41 is an indicator stem 62, which carries a green flag 63, which projects upwardly into a transparent cap 64 provided at the upper end of the interrupter. This clearly indicates to maintenance people, in a positive manner, the fact that the circuit breaker 1 has its contact structure in the fully open circuit position, and that it is then safe to work upon the breaker, if desired.

The three-way valve structure 36 comprises movable valve seats 66, 67, which take care of any misalignment or elongation or contraction of the valve control rods 13, which may be of considerable length. In addition, the valve seats 66, 67 are spring-biased in a direction to effect following travel, once the lips 36a, 36b of the valve 36 has separated therefrom.

To take care of the situation where a low ambient temperature may be encountered, and liquefaction of the sulfur-hexafluoride gas 5 results, liquid pipes may be provided, as indicated by the reference numerals 69 and 70.

The liquefaction pipe 70 communicates with the space below the piston structure 8, which may be at alternately low and high pressure. The liquefaction pipe 69 communicates with the space 56, which is constantly at high pressure. Preferably, ball check valves are provided to prevent the leakage of high-pressure gas admitted from the high-pressure reservoir leaking into the space 39 during low-pressure conditions therein. When the pressure is equalized at the ball valves, the liquid will flow downwardly by gravity down the pipes 69a, 70 and eventually into the high-pressure reservoir 24 within the arcextinguishing chamber, and also within the lower bend 71, where suitably provided heaters 72 may be located to vaporize any liquified gas.

MOVABLE CONTACT STRUCTURE (20) As briefly pointed out hereinbefore, the movable contact structure 20 comprises a generally H-shaped movable contact assemblage 43 secured at its upper end to a yoke-shaped structure 74, which, in turn, is mechanically adjustably secured to the lower end of the piston rod 41. A pair of spaced insulating side operating rods 44, constituting a portion of said H-shaped structure 43, extend interiorly of hollow insulating supporting tubes 45, serving to space the interrupting units 24 axially apart.

With reference being directed particularly to FIG. 8 of the drawings, it will be observed that the yoke structure 74 has a downwardly extending stem portion 75, which is adjustably secured to a hollow movable contact 77. The side operating rods 44 additionally are secured to a movable blast valve activator 79 having a configuration more clearly shown in FIGS. 2123 of the drawings. The movable contact 77 makes separable engagement with a stationary hollow contact structure 81, which is fixably supported upwardly from a base support 83. As shown in more detail in FIG. 8 of the drawings, an exhausting flow of arc-extinguishing fluid 5 at high pressure occurs across the are 85, and diametrically in opposite directions through the interior of both the movable and stationary hollow contacts 77, 81, as indicated by the arrows 86 in FIG. 8.

Generally, there is provided a primary blast valve 88 (FIG. 7) constituted by the lower tip portion 77a of the movable contact 77 making abutting engagement with a relatively stationary primary blast-valve seat 89 (FIG. 7) resiliently supported upon the stationary contact support 83, as shown in FIG. 7. A compression spring 91 provides a desired contact pressure therebetween, and provides for a limited amount of overtravel of the movable contact 77. Additionally, there is provided a plurality of circumferentially disposed stationary contact fingers 82, which make contacting engagement with the external side 77b of the movable tubular contact77.

In addition to the primary blast-valve support, there is provided a pair of secondary downstream blast valves 49, 50, which are closed near the end of the opening operation, as described more clearly hereinafter.

Depending upon the voltage range and current being interrupted, the improved circuit interrupter l of the present invention is adaptable to accommodate one or several arc-extinguishing units 24. FIGS. 5A and 7 illustrate an arrangement in which only a single pair of separable contacts 20 are provided. In the arrangement of FIG. 7, it will be noticed that there is provided a double exhausting flow of gas, inasmuch as both the stationary and movable contacts 77, 81 are hollow, and provide for exhaust outlets therethrough. However, for the high voltage ratings, where a double break is desired, the construction, as set forth in FIG. 9,- may be provided. With reference to FIG. 9, it will be observed that there is provided a pair of serially related arc-extinguishing units 24. In the units 24 shown in FIG. 9, it will be observed that an exhausting flow occurs only through the pair of movable tubular contacts 77, the stationary contacts 81 being closed off, as at 81a. The pair of side operating rods 44 extend downwardly, as illustrated in FIG. 9, having an additional interconnecting yoke portion 95, which again has a downwardly depending stem 96 analogous to the stem 75 illustrated at the upper end of FIG. 8 of the drawings. As a result, the pair of separable contact structures 20 in FIG. 9 are simultaneously actuated.

With reference to FIGS. 1820 of the drawings, it will be apparent that the particular configuration of the circuit breaker structure 1 of the present invention is adapted for various ratings. FIG. 18 shows only a single arc-extinguishing unit 24 in the left-hand leg of the interrupter, whereas the right-hand leg of FIG. 18 constitutes a terminal-bushing structure 28. FIG. 19, on the other hand, shows an arrangement suitable for the higher ratings in which a double-break is afforded. FIG. 19 would, consequently, be similar to an arrangement illustrated structurally more in detail in FIG. 9 of the drawings.

With reference to FIG. 20 of the drawings, it will be observed that in this instance, to adapt the circuit interrupter for the higher ratings, the terminaLbushing structure 28 has been eliminated, and a second arc-extinguishing assemblage constitutes the right-hand leg of the generally Ushaped circuit breaker structure 98. In the latter case, it will be observed that there are consequently afforded three arc-extinguishing units 24 in series.

LATCHING STRUCTURE FOR THE SECONDARY BLAST VALVES (99) The circuit interrupter 1 of the present invention provides a novel means for operating the secondary blast valves 49, 50. On the circuit breaker of the present invention, as previously pointed out, a gas-operated mechanism 101 is used to open and close the contacts of the interrupter 1. The moving contact 77 of the interrupter forms a seal with the mating stationary contacts 81, constituting a primary blast valve 88, so that when the breaker contacts 20 are closed, the seal 88 at the primary blast valve prevents the high-pressure gas from flowing into the center of one or both of the moving separable contacts 77, 81. At this time, the secondary blast valves 49, 50 are open. When the moving contact 77 opens, during the opening operation, the secondary blast valves 49, 50 are going closed to stop the exhausting gas flow into the low-pressure chambers 103-104.

In the circuit-interrupter construction as described, it is desirable that when the contacts 20 of the interrupter open, they arrive in the fully open-circuit position in the shortest period of time. The open position can be reached while there is still an are 85 between the contacts 77, 81. It is quite necessary that the secondary blast valves 49, 50 remain open at this time to allow gas flow to interrupt the are 85. Hence, the secondary blast-valve closing must have a travel curve, which is delayed from that of the moving contacts 77. The following discussion deals with a means of delaying the secondary blastvalve travel.

With reference to FIGS. 7 and 8, it will be observed that the tubular moving contact 77 is directly connected to the mechanism 101, and has a certain travel characteristic. The blast-valve activator 79 is also directly connected to the movable contacts 77, and has, consequently, the same travel. As the movable contact 77 moves to the open position, the blastvalve activator 79 starts compressing a compression spring 105. This compression spring 105 becomes loaded, since the opposite spring seat 106 is prevented from moving, since this spring seat 106 is a part of the blast-valve device, and the blast valve is prevented from moving by two latches 107 (FIG. 15), which are spaced 180 apart. There is some free movement of the activator 79 before starting to compress the compression spring 105, since it is necessary to keep the load on the operating mechanism 101 to a minimum when starting the opening motion. After the activator 79 has moved a specific distance, and thereby compressed the spring 105, protrusions 108 on the activator 79 hit a raised surface 109 on the latches 107, thereby causing the latches 107 to move back, and allow the secondary blast valves 49, 50 to go closed, with a travel curve which is delayed as compared to that of the moving contact 77. When the secondary blast valve 49 is closed, there is some compression on it due to the position of the activator 79 compressing the spring 105 plus a differential pressure holding it closed due to the geometry of the blast-valve face.

When the circuit breaker contacts 77 are closed, the secondary blast valves 49, 50 are open. The activator 79, with its rubber bumper 111, strikes the secondary blast valve 49 and moves it to the open position. A small gas dashpot is also formed between the activator 79 and the blast valve 49 to help reduce the shock. At this time, the latches 107 fall under the shoulders 49a (FIG. 9) and the blast valve 49 is ready for another opening operation.

The pneumatic mechanism 101 disposed within the cap structure 114 and concerning the dual action of the piston 8 is set forth and claimed in U.S. Pat. application, filed Dec. 10, 1968, Ser. No. 782,63l by William H. Fischer and Wayne S. Aspey and assigned to the assignee of the present invention.

OPTIONAL TERMINALBUSHING STRUCTURE As previously mentioned, for the lower ratings, instead of using an arc-extinguishing assemblage 15 on the right-hand leg of the U-shaped circuit interrupter 1, a terminal-bushing structure 28 may be employed. With reference to FIG. 5C ol' the drawings, it will he observed that there is provided an axially extending high-voltage terminal stud 29 having a threaded upper end 29a. Surrounding said terminal stud 29, in spaced relation therewith, is an outer weatherproof insulating shell, or casing 30 having a plurality of weather sheds 30a thereon for increased surface creepage distance. Although the sulfur-hexafluoride (SF gas in the lower U-haped bend is at a pressure, say, for example, 230 p.s.i., it is nevertheless desirable to reduce the pressure acting internally upon the weatherproof casing 30. For this purpose, it is desirable to reduce the pressure to a much lower value, say, for example, 25 psi. This may be accomplished by a pressure-reducing valve, not shown, interconnecting the high-pressure space 117 (FIG. 58) with the space 118 interiorly of the weatherproof casing 30.

A frustoconieal insulating supporting member 119 is used to provide a barrier between the high-pressure region 117 and the relatively low-pressure region 118. In addition, to maintain compressive stress upon the weatherproof casing 30, a battery of compression springs 121 is interposed between an upper disc-shaped spring seat 122 and a lower pressure plate 123, which acts upon the upper end of the weatherproof casing 30. A nut 125 which may be screwed onto the upper end of the terminal stud 29, may be used to adjustably regulate the pressure exerted by the battery of compression springs 121. A flexible cup 127 may be interposed between the pressure plate 123 and the upper extremity of the weatherproof shell 30. This cup 127 may be spun from suitable metal, such as copper or aluminum, and may be soldered to an upper cap portion 129, which, in turn, may be brazed, or otherwise suitably secured, to a protective plate 131. An upper nut 133 may be screwed upon the upper extremity 29a of the terminal stud 29, and there bear directly upon the upper face of the protective plate 131. I

The lower end of the weatherproof casing 30 may have an annular flange 135 secured thereto, which, inturn, may be bolted by a plurality of circumferentially spaced bolts 137 to the supporting flange 138, which is, in turn, welded, or otherwise secured, to an upper cylindrical portion 140 (FIG. 5B) of the lower U-shaped high-pressure bend reservoir 71, as shown more clearly in FIG. 5B of the drawings.

For the measurement of current passing through the circuit interrupter, one or more current transformers CT may be utilized surrounding the high-pressure reservoir 71, and constituting a secondary winding for the primary winding, which is constituted by the inner high-voltage terminal stud 29.

FIG. 53 also illustrates the lower end of the valve-control rod 13, which extends through a seal 13a and externally into the atmosphere, where it is connected to a bellcrank lever 141. As shown in FIG. 4, the bellcrank lever is pivotally secured upon a stationary pivot 142, and transmits motion from a pair of links 143, 144, which, in turn, are connected to the operating mechanism 10 illustrated in FIG. 4. The mechanism 10 may be of a type set for in U.S. Pat. filed Nov.

18, 1968, Ser. No. 776,510, by William H. Fischer and Wayne With reference to FIGS. 58 and 10, it will be observed that the high-pressure reservoir 71, containing gas at a pressure of say, for example, 230 p.s.i., is constituted by a three-part flanged cylindrical supporting construction 71a, 71b and 71c, bolted together, as by mounting bolts, with gaskets interposed therebetween, and surrounding the inner conducting stud 29 at high voltage for the circuit interrupter 1. As a result, this not only provides a high-pressure reservoir 71 for admittance of high-pressure gas upwardly into the space 47 externally of the arc-extinguishing units 24, but also, due to the high pressure, permits a close spacing between the inner high-voltage conductor stud 29 and the grounded U-shaped casing 71. In addition, this provides a compact construction with ready accessibility provided for maintenance operations, when desired.

A boss portion (not shown) is welded to the side of the lower end of the bend 71, and has a hole bored therethrough, permitting the passage of high-pressure gas from the highpressure lower bend 71 to the operating mechanism 10, which utilizes high-pressure SF has as an operating fluid for a piston structure (not shown) to force the linkage, within the operating mechanism 10, to its closed-circuit position.

From the foregoing description it will be apparent that there has been provided an improved compressed-gas circuit interrupter 1 of such configuration, that it is adaptable for various voltage ratings, while at the same time permitting the use of identical parts for the several ratings. For instance, it will be observed that with reference to FIGS. 18 and 19, the same terminal-bushing structure 28 may be present at the right-hand leg of the circuit breaker, whereas only a modification of the left-hand leg to accommodate one or several serially related pairs of contacts 20 is necessary. Additionally, for the higher ratings, the terminal-bushing structure 28 of H68. 18 and 29 may be omitted, and a second arc-extinguishing assemblage 15, similar to that of the left-hand legs of FIGS. 18 and 19, may be used as the right-hand leg of the higher-rating breaker of FIG. 20. The adaptability and the use of identical parts is, therefore, obvious.

The foregoing construction renders a compact circuit interrupter 1 possible, and highly efficient flow conditions are assured by the separation of the contacts 20 within a high-pressure gaseous environment 47. The exhausting gas flow during the opening operation is collected in the low-pressure chambers 103, 104, and eventually is conducted by means of the hollow operating-rod tubes 17 down to the low-pressure tank 113 at the base 2 of the supporting framework, as clearly illustrated in FIG. 1 of the drawings. A suitable compressor, not shown, is used to recompress the gas to the high-pressure level of 220 p.s.i.

Although there has been illustrated and described specific structures, it is to be clearly understood that the same were merely for the purpose of illustration, and that changes and modifications may be made therein by those skilled in the art,

without departing from the spirit and scope of the invention.

We claim:

1. A circuit interrupter of generally U-shaped configuration comprising, in combination:

a. a grounded lower portion including a high-pressure U- shaped grounded pressurized casing containing high-pres sure gas;

b. an arc-extinguishing assemblage including one or more compressed-gas interrupting units constituting one upstanding leg of the U;

c. a terminal-bushing structure constituting the other leg of the U.

2. The combination of claim 1, wherein the terminal-bushing structure includes a weatherproof casing containing the same gas at a reduced pressure.

3. The combination of claim 1, wherein the one or more compressed-gas interrupting units contain separable contacts closed in a high-pressure gaseous environment.

4. The combination of claim 1, wherein a pneumatic operator for the contact structure of the one or more interrupting units is located at the upper extremity of the arc-extinguishing assemblage (15).

5. The combination of claim 4, wherein a three-way control valve controlling the pneumatic operator and has an insulating control rod extending down interiorly of the assemblage to ground potential.

6. A compressed-gas circuit interrupter of generally U- shaped configuration comprising, in combination:

a. a grounded lower frame portion including a high-pressure U-shaped grounded tube containing high-pressure gas;

b. a high-voltage conductor extending through said pressurized tube;

c. a compressed-gas arc-extinguishing assemblage including one or more compressed-gas interrupting units constituting one generally upstanding leg of the U; another areextinguishing assemblage including one or more compressed-gas interrupting units constituting the other upstanding leg of the U.

7. The combination according to claim 6, wherein each of the arc-extinguishing assemblages includes separable contacts which are closed in a high-pressure gaseous environment.

8. The combination according to claim 6, wherein current transformers encircle the lower grounded pressurized tube.

9. The combination according to claim 3, wherein the arcinterrupting units have at least one hollow tubular contact through which gas is exhausted to a low-pressure region during the opening operation.

10. The combination according to claim 1, wherein the easing for the arc-extinguishing assemblage includes an outer weatherproof insulating casing and an inner high-strength insulating tube, and the space intervening between said casings is at an intermediate pressure between atmospheric pressure and the high-pressure existing within the inner high-strength tube.

11. The combination according to claim 4, wherein a signal indicator is affixed to the piston stem for the pneumatic operator and is visible by maintenance people externally of the circuit interrupter.

12. The combination according to claim 2, wherein a generally frustoconical supporting member insulatingly supports the high-voltage conductor stud within the terminalbushing structure and additionally provides a barrier between the high-pressure within the lower grounded pressurized casing and the region interiorly of the terminal-bushing weatherproof casing. 

1. A circuit interrupter of generally U-shaped configuration comprising, in combination: a. a grounded lower portion including a high-pressure U-shaped grounded pressurized casing containing high-pressure gas; b. an arc-extinguishing assemblage including one or more compressed-gas interrupting units constituting one upstanding leg of the U; c. a terminal-bushing structure constituting the other leg of the U.
 2. The combination of claim 1, wherein the terminal-bushing structure includes a weatherproof casing containing the same gas at a reduced pressure.
 3. The combination of claim 1, wherein the one or more compressed-gas interruptiNg units contain separable contacts closed in a high-pressure gaseous environment.
 4. The combination of claim 1, wherein a pneumatic operator for the contact structure of the one or more interrupting units is located at the upper extremity of the arc-extinguishing assemblage (15).
 5. The combination of claim 4, wherein a three-way control valve controlling the pneumatic operator and has an insulating control rod extending down interiorly of the assemblage to ground potential.
 6. A compressed-gas circuit interrupter of generally U-shaped configuration comprising, in combination: a. a grounded lower frame portion including a high-pressure U-shaped grounded tube containing high-pressure gas; b. a high-voltage conductor extending through said pressurized tube; c. a compressed-gas arc-extinguishing assemblage including one or more compressed-gas interrupting units constituting one generally upstanding leg of the U; another arc-extinguishing assemblage including one or more compressed-gas interrupting units constituting the other upstanding leg of the U.
 7. The combination according to claim 6, wherein each of the arc-extinguishing assemblages includes separable contacts which are closed in a high-pressure gaseous environment.
 8. The combination according to claim 6, wherein current transformers encircle the lower grounded pressurized tube.
 9. The combination according to claim 3, wherein the arc-interrupting units have at least one hollow tubular contact through which gas is exhausted to a low-pressure region during the opening operation.
 10. The combination according to claim 1, wherein the casing for the arc-extinguishing assemblage includes an outer weatherproof insulating casing and an inner high-strength insulating tube, and the space intervening between said casings is at an intermediate pressure between atmospheric pressure and the high-pressure existing within the inner high-strength tube.
 11. The combination according to claim 4, wherein a signal indicator is affixed to the piston stem for the pneumatic operator and is visible by maintenance people externally of the circuit interrupter.
 12. The combination according to claim 2, wherein a generally frustoconical supporting member insulatingly supports the high-voltage conductor stud within the terminal-bushing structure and additionally provides a barrier between the high-pressure within the lower grounded pressurized casing and the region interiorly of the terminal-bushing weatherproof casing. 